There's no point being the maintainer of an Operating System that can't boot to the home screen on its flagship device for lack of GPU support, especially when I'm getting the blame for something that I don't have authority to fix myself and that I had anticipated and escalated more than 6 months ahead.

By the way, in this context, 'to escalate' means handing something over to your superiors so they can handle it. I believe this definition of the word is uncommon outside of the US.

The issue here is exactly what it sounds like: there are currently no factory images/binaries available for the latest Nexus device, the new Nexus 7. The problem is that the GPU in the new Nexus 7 is made by Qualcomm, a company which is incredibly hostile towards the open source community. This isn't the first time Qualcomm has sabotaged an AOSP launch - all Nexus devices with Qualcomm chips, the Nexus 1, 4, and the new 7, faced these problems.

Because he is apparently very good at pattern recognition, JBQ states that he already anticipated this issue six months ago, but that it hasn't been solved. A recent tweet from him is quite telling:

This is bad news for Google, and bad news for Android. JBQ has done an amazing job on AOSP, and I'm very sad to see him leaving his post. As of this moment, it's not yet known whether he will leave Google entirely or not.

Seriously? How 'bout Google needs to realize that they can't accomplish ideological goals based on their suppliers which have completely independent goals of their own, suck it up, take some accountability, and make it clear that they will compromise ideological values based on technical needs... or they need to start producing the types of chips they want with the values they want... rather than proclaiming the rest of the industry which is going about pursuing its own goals as best it sees fit regardless of what Google would want or hope for?

The idea that ARM needs to produce a new ARM design so that some other SOC developer can build a chip which may or may not have the values as Google or that some other SOC manufacturer is going to spring up with Google's values in mind and also deliver the best chip for the purpose in high volumes, with a rapid upgrade cycle such that it becomes the OEMs go to choice for smartphone development is hysterically laughable.